/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.client;

import java.util.Map;

import org.apache.hbase.thirdparty.com.google.common.collect.Maps;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.hadoop.hbase.exceptions.DeserializationException;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.io.TimeRange;
import org.apache.hadoop.hbase.security.access.AccessControlConstants;
import org.apache.hadoop.hbase.security.access.AccessControlUtil;
import org.apache.hadoop.hbase.security.access.Permission;
import org.apache.hadoop.hbase.security.visibility.Authorizations;
import org.apache.hadoop.hbase.security.visibility.VisibilityConstants;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;

import org.apache.hbase.thirdparty.com.google.common.collect.ArrayListMultimap;
import org.apache.hbase.thirdparty.com.google.common.collect.ListMultimap;
import org.apache.hadoop.hbase.util.Bytes;

/**
 * Base class for HBase read operations; e.g. Scan and Get.
 */
@InterfaceAudience.Public
public abstract class Query extends OperationWithAttributes {
    private static final String ISOLATION_LEVEL = "_isolationlevel_";
    protected Filter filter = null;
    protected int targetReplicaId = -1;
    protected Consistency consistency = Consistency.STRONG;
    protected Map<byte[], TimeRange> colFamTimeRangeMap = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
    protected Boolean loadColumnFamiliesOnDemand = null;

    /**
     * @return Filter
     */
    public Filter getFilter() {
        return filter;
    }

    /**
     * Apply the specified server-side filter when performing the Query. Only
     * {@link Filter#filterCell(org.apache.hadoop.hbase.Cell)} is called AFTER all tests for ttl,
     * column match, deletes and column family's max versions have been run.
     * @param filter filter to run on the server
     * @return this for invocation chaining
     */
    public Query setFilter(Filter filter) {
        this.filter = filter;
        return this;
    }

    /**
     * Sets the authorizations to be used by this Query
     * @param authorizations
     */
    public Query setAuthorizations(Authorizations authorizations) {
        this.setAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY, ProtobufUtil.toAuthorizations(authorizations).toByteArray());
        return this;
    }

    /**
     * @return The authorizations this Query is associated with.
     * @throws DeserializationException
     */
    public Authorizations getAuthorizations() throws DeserializationException {
        byte[] authorizationsBytes = this.getAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY);
        if(authorizationsBytes == null)
            return null;
        return ProtobufUtil.toAuthorizations(authorizationsBytes);
    }

    /**
     * @return The serialized ACL for this operation, or null if none
     */
    public byte[] getACL() {
        return getAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL);
    }

    /**
     * @param user User short name
     * @param perms Permissions for the user
     */
    public Query setACL(String user, Permission perms) {
        setAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL, AccessControlUtil.toUsersAndPermissions(user, perms).toByteArray());
        return this;
    }

    /**
     * @param perms A map of permissions for a user or users
     */
    public Query setACL(Map<String, Permission> perms) {
        ListMultimap<String, Permission> permMap = ArrayListMultimap.create();
        for(Map.Entry<String, Permission> entry : perms.entrySet()) {
            permMap.put(entry.getKey(), entry.getValue());
        }
        setAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL, AccessControlUtil.toUsersAndPermissions(permMap).toByteArray());
        return this;
    }

    /**
     * Returns the consistency level for this operation
     * @return the consistency level
     */
    public Consistency getConsistency() {
        return consistency;
    }

    /**
     * Sets the consistency level for this operation
     * @param consistency the consistency level
     */
    public Query setConsistency(Consistency consistency) {
        this.consistency = consistency;
        return this;
    }

    /**
     * Specify region replica id where Query will fetch data from. Use this together with
     * {@link #setConsistency(Consistency)} passing {@link Consistency#TIMELINE} to read data from
     * a specific replicaId.
     * <br><b> Expert: </b>This is an advanced API exposed. Only use it if you know what you are doing
     * @param Id
     */
    public Query setReplicaId(int Id) {
        this.targetReplicaId = Id;
        return this;
    }

    /**
     * Returns region replica id where Query will fetch data from.
     * @return region replica id or -1 if not set.
     */
    public int getReplicaId() {
        return this.targetReplicaId;
    }

    /**
     * Set the isolation level for this query. If the
     * isolation level is set to READ_UNCOMMITTED, then
     * this query will return data from committed and
     * uncommitted transactions. If the isolation level
     * is set to READ_COMMITTED, then this query will return
     * data from committed transactions only. If a isolation
     * level is not explicitly set on a Query, then it
     * is assumed to be READ_COMMITTED.
     * @param level IsolationLevel for this query
     */
    public Query setIsolationLevel(IsolationLevel level) {
        setAttribute(ISOLATION_LEVEL, level.toBytes());
        return this;
    }

    /**
     * @return The isolation level of this query.
     * If no isolation level was set for this query object,
     * then it returns READ_COMMITTED.
     * @return The IsolationLevel for this query
     */
    public IsolationLevel getIsolationLevel() {
        byte[] attr = getAttribute(ISOLATION_LEVEL);
        return attr == null ? IsolationLevel.READ_COMMITTED : IsolationLevel.fromBytes(attr);
    }

    /**
     * Set the value indicating whether loading CFs on demand should be allowed (cluster
     * default is false). On-demand CF loading doesn't load column families until necessary, e.g.
     * if you filter on one column, the other column family data will be loaded only for the rows
     * that are included in result, not all rows like in normal case.
     * With column-specific filters, like SingleColumnValueFilter w/filterIfMissing == true,
     * this can deliver huge perf gains when there's a cf with lots of data; however, it can
     * also lead to some inconsistent results, as follows:
     * - if someone does a concurrent update to both column families in question you may get a row
     *   that never existed, e.g. for { rowKey = 5, { cat_videos =&gt; 1 }, { video =&gt; "my cat" } }
     *   someone puts rowKey 5 with { cat_videos =&gt; 0 }, { video =&gt; "my dog" }, concurrent scan
     *   filtering on "cat_videos == 1" can get { rowKey = 5, { cat_videos =&gt; 1 },
     *   { video =&gt; "my dog" } }.
     * - if there's a concurrent split and you have more than 2 column families, some rows may be
     *   missing some column families.
     */
    public Query setLoadColumnFamiliesOnDemand(boolean value) {
        this.loadColumnFamiliesOnDemand = value;
        return this;
    }

    /**
     * Get the raw loadColumnFamiliesOnDemand setting; if it's not set, can be null.
     */
    public Boolean getLoadColumnFamiliesOnDemandValue() {
        return this.loadColumnFamiliesOnDemand;
    }

    /**
     * Get the logical value indicating whether on-demand CF loading should be allowed.
     */
    public boolean doLoadColumnFamiliesOnDemand() {
        return (this.loadColumnFamiliesOnDemand != null) && this.loadColumnFamiliesOnDemand;
    }

    /**
     * Get versions of columns only within the specified timestamp range,
     * [minStamp, maxStamp) on a per CF bases.  Note, default maximum versions to return is 1.  If
     * your time range spans more than one version and you want all versions
     * returned, up the number of versions beyond the default.
     * Column Family time ranges take precedence over the global time range.
     *
     * @param cf       the column family for which you want to restrict
     * @param minStamp minimum timestamp value, inclusive
     * @param maxStamp maximum timestamp value, exclusive
     * @return this
     */

    public Query setColumnFamilyTimeRange(byte[] cf, long minStamp, long maxStamp) {
        colFamTimeRangeMap.put(cf, new TimeRange(minStamp, maxStamp));
        return this;
    }

    /**
     * @return A map of column families to time ranges
     */
    public Map<byte[], TimeRange> getColumnFamilyTimeRange() {
        return this.colFamTimeRangeMap;
    }
}
